Long Beach goes months without real rain. Then the first storm of the season hits, and suddenly the 405, the 710, and every intersection on Cherry and Paramount turn into a skating rink. That's not your imagination. The first rain after a dry spell is the slickest road you'll drive all year.
Why the First Rain Is the Worst
All summer, cars drip oil, grease, and coolant onto the road, and tires leave behind a thin layer of rubber. With no rain to wash it off, that film builds up for months.
When the first rain falls, the water lifts the oil to the surface instead of washing it away right away. You end up driving on a layer of oil floating on water. It's worst in the first hours of the storm. Once steady rain has rinsed the road, grip improves. A light drizzle is actually worse than a downpour, because there's enough water to lift the oil but not enough to wash it off.
Your tires are the only thing between your car and that road. That's why their condition matters most on the first wet day.
Tread Depth: The Number That Matters in the Rain
The grooves in your tread do one job in the rain: they push water out from under the tire so the rubber can touch the road. As tread wears down, the grooves get shallower and move less water. At highway speed, a worn tire can ride up on a layer of water. That's hydroplaning.
6/32" or more
Good for wet roads. Most new tires start at 10/32" to 11/32".
4/32"
Time to shop. Wet grip drops off sharply from here. Replace before the rainy season.
2/32"
The legal minimum in California, and unsafe in the rain. Replace now.
The quarter test: Put a quarter head-first into a main groove with Washington's head facing you. If you can see the top of his head, you're at 4/32" or less. Check the inner, center, and outer grooves on each tire. Tires often wear unevenly, and one bald edge is enough to lose grip. If one edge is worn much more than the rest, read what uneven tire wear means.
Tire Pressure and Tire Age
Pressure: An underinflated tire flattens out and can't push water out of its grooves as well. Check pressure when the tires are cold, before you drive, and set it to the number on the sticker on your driver's door jamb, not the maximum printed on the tire. Temperatures drop in the fall, and tire pressure drops with them, so a pressure that was right in August can be low in November.
Age: Southern California sun bakes tires. The rubber hardens over the years, and hard rubber grips poorly on wet roads, even with plenty of tread left. Find the four-digit date code on the sidewall: 2319 means the 23rd week of 2019. If your tires are more than 6 years old, have them checked before the rain. For more, read how long tires last in Southern California.
Don't Forget Brakes, Wipers, and Lights
- Brakes: Wet roads make stopping distances longer, and worn pads make it worse. If your brakes squeak, grind, or feel soft, find out what the noise means. Brake inspections are free at both shops.
- Wipers: Summer heat cracks wiper blades. If they streak or chatter on the first rain, replace them.
- Headlights: California law requires headlights on whenever your wipers run continuously.
If Your Car Hydroplanes
You'll feel the steering go light, and the engine may rev as the tires lose contact with the road. What to do:
- Take your foot off the gas. Don't brake hard.
- Hold the steering wheel steady, pointed where you want to go.
- Let the car slow down until the tires touch the road again.
To avoid it in the first place: slow down, turn off cruise control, stay out of standing water, and follow the tire tracks of the car ahead, where there's less water.
At 2/32" or less, don't wait for the rain. Bald tires don't have enough tread to clear water at any speed. Replace them now.
Get Rain-Ready at Ochoa's
Stop by either Long Beach shop and we'll measure your tread, check the date codes, and set your pressure. If you need tires, we get any size same day or next day. We sell inspected used tires from $45 with at least 4/32" of tread, and new tires from brands including Pirelli, Falken, and Nexen. Snap financing is available, with no credit needed.
Frequently Asked Questions
Why are roads so slippery during the first rain?
During dry months, oil, grease, and rubber from tires build up on the road surface. The first rain lifts that film to the top of the water before it can wash away, so the road is slicker than in a normal rain. It's worst in the first hours of the storm and gets better as steady rain rinses the road.
How much tread do I need for driving in the rain?
California's legal minimum is 2/32 of an inch, but that's too little for wet roads. Wet grip drops off sharply below 4/32 of an inch, because shallow grooves can't move water out from under the tire fast enough. If you're at 4/32 or less, replace your tires before the rainy season.
How do I check my tread depth without a gauge?
Use a quarter. Put it head-first into a main groove with Washington's head facing you. If you can see the top of his head, you're at 4/32 of an inch or less. Check the inner, center, and outer grooves on every tire, because worn suspension or alignment problems often wear one edge first.
What should I do if my car hydroplanes?
Take your foot off the gas, keep the steering wheel pointed where you want to go, and don't slam the brakes. Let the car slow down until the tires touch the road again. If you have to brake, press gently. Anti-lock brakes pulse on their own, so hold steady pressure and don't pump them.
Do I need to turn my headlights on when it rains in California?
Yes. California law requires your headlights to be on whenever conditions need your windshield wipers to run continuously. Turn them on as soon as the wipers are on.
Have this problem right now? Our Cherry Ave shop is open 7 days a week and Paramount is open Monday through Saturday — no appointment needed for most services.